Drupal 8 & Symfony

by Daniel Lemon

@dan2k3k4

What is Symfony?

Symfony is an Open Source distributed PHP framework.

It is component-based, and offers extensive modularity.

Great community with a lot of learning resources.

Follows coding standards up to PSR-4.

@dan2k3k4

Symfony Community

Over 1600 contributors to Symfony

@dan2k3k4

Symfony User Group Basel
Opening hosted by:
IWF Web Solutions
in Basel, Switzerland
February 22, 2017
(from 19:30 to 21:00)
 

Projects using Symfony

A subset of Symfony Components are used:

@dan2k3k4

...and of course: Drupal 8

Symfony Documentation

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http://symfony.com/doc/current/index.html

Drupal 7

Module development

@dan2k3k4

.inc files

global_function_name()

procedural

Call & override different hooks e.g.

// Implements hook_menu().
function mymodule_menu() {}

Drupal 7

mymodule.info

@dan2k3k4

name = mymodule
description = A simple hello world module
package = custom
version = 1.0
core = 7.x
files[] = mymodule.module

mymodule.module

<?php
function mymodule_menu() { // oh why snake why?!
    $items = array(); // uh, let's move to: []

    $items['my_module/hello_world'] = array(
        'title' => 'Hello World Example',
        'page callback' => 'say_hello_world',
        'access arguments' => array('access content'),
        'type' => MENU_CALLBACK,
     );

    return $items;
}

function say_hello_world() {
    $vars = array();
    $vars['type'] = "div";
    $vars['title'] = "";
    $vars['attributes'] = array("");
    $vars['items'][] = "Hello from the other side...";

    return theme_item_list($vars);
}

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Drupal 8

require Symfony/Components

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Object oriented

Decoupled

Easily testable

Drupal 8

Module folder structure

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mymodule/
  src/
    Controller/
      MyModuleController.php
  mymodule.info.yml
  mymodule.module

mymodule.info.yml

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MyModuleController.php

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<?php
/**
 * @file
 * Contains \Drupal\mymodule\Controller\MyModuleController.
 */
namespace Drupal\mymodule\Controller;

class MyModuleController {
  public function content() {
    return array(
      '#type' => 'markup',
      '#markup' => t('...I must have git pushed a thousand times'),
    );
  }
}

Bundle? Component?

Symfony Bundles are to Symfony as modules are to Drupal

Symfony Components are a set of decoupled and reusable PHP libraries

Components are becoming the standard foundation to build the best PHP applications

@dan2k3k4

Symfony bundle

Bundle directory structure

@dan2k3k4

Command
Controller
DependencyInjection
    CompilerPass
EventListener
Resources
    config
        services
            some_definitions.yml
Tests
VendorProjectBundle.php

Symfony bundle

Basic Controller

@dan2k3k4

<?php

namespace Davos\MountainCampBundle\Controller;

use Symfony\Component\HttpFoundation\Response;

class GrueziController
{
    public function halloAction()
    {
        return new Response('Grüezi y\'all howzit! 🇨🇭 🇺🇸 🇿🇦');
    }
}

Components Used

don't reinvent the wheel...

@dan2k3k4

• ClassLoader
• CssSelector
• DependencyInjection
• EventDispatcher
• HttpFoundation
• HttpKernel

• Process
• Routing
• Serializer
• Validator
• Yaml

EventDispatcher

What's that?

@dan2k3k4

provides tools to allow your application components to communicate with each other by dispatching events and listening to them.

Subscribe to events elsewhere with the EventSubscriber

HttpKernel

What's that?

@dan2k3k4

Provides a structured process for converting a Request into a Response by making use of the EventDispatcher component.

http://symfony.com/doc/current/components/http_kernel.html

Dependency Injection

...inject all the code

@dan2k3k4

Service Container

A Service Container can be used to efficiently manage services in an application.
 

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Service Container

 Register Event Listeners in the Service Container 

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Event

E

E

E

E

Form

Event
Dispatcher

SendMail

CreateUser

etc.

Injection Types

choose your needle

@dan2k3k4

Constructor

Setter

Property
Interface

__construct(Response $response, ...)

setResponse(Response $response)

$container->setProperty('mailer', new Reference('mailer'))

class StaticController implements ControllerInterface

$container->get('httpkernel.response');

Container

Constructor Injection

Most common way to inject dependencies

@dan2k3k4

  path.alias_manager:
    class: Drupal\Core\Path\AliasManager
    arguments: [
      '@path.alias_storage',
      '@path.alias_whitelist',
      '@language_manager',
      '@cache.data'
    ]

\web\core\core.services.yml

Code Conventions

...and PHP Standard Recommendations

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Code Style Guide
Design Patterns

S.O.L.I.D

• Single-responsiblity
• Open-closed
• Liskov substitution
• Interface segregation
• Dependency Inversion Principle

Code Conventions

...and PHP Standard Recommendations

@dan2k3k4

Reusable
Extendable
Modifiable
Testable
Refactorable

Let's Recap

What should I do as a Drupal developer?

@dan2k3k4

• Don't just port a D7 module to D8
  • think about the architecture
• Learn 'some' Symfony
• Learn PHP coding standards
• Reuse libraries
• Open source and contribute back
• Have fun

http://slides.com/dan2k3k4/drupal-8-symfony/fullscreen

@dan2k3k4